Why comedogenic ratings aren't a good guide?

Relying on comedogenic charts or tools to determine whether an ingredient causes acne might seem like a straightforward approach. However, the truth is, this clear and simple method is likely flawed when addressing the complex issue of acne causation.

Why?

The comedogenicity scale, ranging from 0 (fine) to 5 (danger ahead), originates from academic models that oversimplify the real-world complexity of acne. These models often rely on rabbit ear tests, as human subjects are too variable. Unfortunately, what's comedogenic for a rabbit might not hold true for human skin, especially since we're less sensitive. Moreover, an ingredient considered comedogenic in isolation might not have the same effect when diluted in a product, and ingredients can interact in unexpected ways. Additionally, the individual's unique skin chemistry and batch-to-batch variability during production further complicate matters. As Dr. Kligman, the creator of the comedogenic scale, stated, "you cannot determine from a reading of the ingredients whether a given product will be acnegenic or not."

What should you do?

TRUST YOUR OWN EXPERIENCES.

If a product contains numerous highly comedogenic ingredients (rated 4-5), particularly near the top of the list, you might want to reconsider. If it includes one such ingredient, patch test it to observe real-world effects, as personal experiences outweigh internet-based guesswork.

TRUST YOUR OWN EXPERIENCES.

If you notice breakouts within a month of using a product, check for severely comedogenic ingredients high on the list as a starting point. However, remember that other factors may be at play, and consider whether other products with similar ingredients don't cause breakouts.

TRUST YOUR OWN EXPERIENCES.

Patch test everything, especially undiluted natural oils and butters.

In summary - TRUST YOUR OWN EXPERIENCES.

What shouldn't you do?

- Use comedogenicity ratings as a lazy way to avoid patch testing new products.
- Witch hunt products or make wild predictions of suitability based on a comedogenic scale you saw.
- Refuse to buy a product solely because it contains a comedogenic ingredient, especially if it's low down in the ingredient list (considering dilution).
- Assume that an undiluted oil acts the same as an oil in a formulation; there's no straightforward relationship as fatty acids are chemically bound in a formulation, altering their behaviour.

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